# calculus

posted by
**Febby**
.

1) Integrate Cos^n(x) dx

2) Integrate e^(ax)Sinbx dx

3) Integrate (5xCos3x) dx

I Will be happy to critique your thinking on these.

1) Derive a recursive relation.

2) Simplest by replacing sin(bx) by

Exp[i b x] and taking imaginary part at the end.

3)

First integrate sin(yx) and then differentiate the answer w.r.t. y.